In defending oneself or a particular point of view, it is important to have a variety of ways to express that sentiment. Some useful synonyms for "in defense" include "in support of," "in favor of," "on behalf of," "protecting," "championing," "upholding," "advocating," "justifying," "endorsing," and "standing up for." Each of these phrases can be used to convey the idea that someone or something is being protected or supported, and can be used interchangeably with "in defense" in many contexts. Whether you are writing an essay, engaging in a debate, or simply expressing your opinion, these synonyms can help you articulate your position with clarity and precision.